French intelligence officials who'd been monitoring Saïd and Chérif Kouachi made tragic—if arguably understandable—decisions in recent years to drop surveillance of the brothers, a New York Times piece reports. Intelligence authorities stopped following Chérif Kouachi in 2013 and stopped following his brother in 2014; agents reporting to domestic intelligence chief Patrick Calvar let an order allowing surveillance on Saïd expire only seven months before the pair murdered 12 at the offices of Charlie Hebdo.
Current and former officials say the surveillance on the Kouachis had turned up nothing to indicate that they were an imminent threat. They point to the lack of resources to conduct physical surveillance on large numbers of targets, estimating that 25 agents, working in shifts, are required to watch over a single person day and night.
“You can’t follow everyone,” said Bernard Squarcini, who was Mr. Calvar’s predecessor as head of the domestic intelligence agency and was in charge when the Kouachis were placed under surveillance after a tipoff from the United States in 2011. “These were two inactive targets that had been quiet for a long time. They were giving nothing away.”
Compounding the brothers' inaction was increasing emphasis among intelligence groups on monitoring radicalized militants returning from time with ISIS in Syria. The Kouachis were known to authorities because Chérif had traveled to Yemen, the home of extensive al-Qaida activity, in 2011 with his brother's passport. But they were not among the 1,400 French residents believed to have joined or attempted to join jihadist causes in Iraq and Syria in recent years, and during their attack they claimed loyalty to al-Qaida in the Arabian Peninsula rather than ISIS.
On a procedural level, the Times notes, French intelligence services have limited investigative tools. The intelligence services, for example, can monitor cell phones but can't bug apartments or seize computers—and as one official puts it in the Times piece, "No one talks on the phone anymore."